Line spacing mechanism for typewriters and like business machines



April 1962 b P WILLIAMS 3,031,057

LINE SPACING MEbI-IANISM FOR TYPEWRITERS AND LIKE BUSINESS MACHINES Filed Feb. 20, 1961 Fig.1

INVENTOR OLIN P. WILLIAMS ilnited States 3,031,057 LINE SPACING MECHANISM FOR TYPEWRITERS AND LIKE BUSINESS MACPHNES Olin P. Williams, West Hartford, Conn, assignor to Royal McBee Corporation, Port Chester, N.Y., a corporation of New York Filed Feb. 20, 1961, Ser. No. 90,458 4 Claims. (Cl. 197114) This invention relates to line spacing mechanism for typewriters or like business machines; more particularly it relates to line spacing mechanism characterized by control means operable to effect uniform line spacing from any position of the machine carriage; and specifically it relates to line spacing mechanism wherein said control means may be operated repeatedly for as long as a line space function control key is held depressed.

In electric typewriters presently in use line spacing is effected upon rotation of a ratchet either by a pawl operable in response to the pull of the carriage return draw band, or by a pawl secured on one end of and operable in response to the partial rotation of a repeat line space bail supported by the typewriter carriage. The line bail is actuated by an element whose position is fixed relative to the typewriter frame. As the typewriter carriage moves in letter space direction then, the distance between the pawl and the actuating element increases. As this distance increases the torsional deflection experienced by the bail also increases with the result that when the distance between actuating element and the pawl end of the bail is appreciable, the pawl end does not rotate sufliciently to impart a full stroke to the pawl to effect a uniform line space increment.

As a result of the above machines having extra long carriages are not provided with line space mechanism operable from any carriage position.

In accordance with the instant invention there is provided mechanism adaptable to carriages of any length for effecting line spacing or uniform repeat line spacing from any position of the carriage. Briefly, the mechanism comprises a dimensionally stable taut cable secured at one end to a pawl crank arm supported by the carriage adjacent the line space ratchet, and at the other end to the opposite end of the carriage. Looping the cable between the fixed and movable support results in movement of the latter thereby effecting a line space.

An object of the invention is in the provision of novel line spacing mechanism controllable from any carriage position.

A further object of the invention is in the provision of a dimensionally stable cable for transmitting uniform motion to a line space mechanism in response to a uniform stimulus applied to said cable at any point along its length.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIGURE 1 is a rear view showing line spacing mechanism in accordance with the invention.

FIGURE 2 is a cross sectional view taken along lines 2-2 of FIGURE 1.

Referring now to the drawings wherein like reference numerals represent like or corresponding parts throughout the views, there is shown in FIGURE 1 a carriage generally designated by reference numeral 10, comprising spaced end plates 12 and 14 adapted to rotatably support a platen v16 which has provided on its right end, as viewed 3,031,057 Patented Apr. 24, 1962 in the figure, a ratchet wheel 18. As shown in FIGURES 1 and 2 the end plates mount a cross shaft 20 which rotatably supports a lever arm 22. The lever arm is articulately connected as at 24 to an actuator pawl 26 Which extends through a slot 28 formed in a guide 30 fixed to and depending from a cross bar 31 forming part of the carriage frame structure. The slot 28 is elongated vertically so as to enable the pawl 26 to move vertically as Well as substantially horizontally with respect to guide 30. The pawl 26 has a pointed front end or nose 32 which normally is retracted from the ratchet wheel under the action of the lever arm 22 and lever arm return spring 34 connected at its lower end to the lever arm as at 36 and at its other end to a fixed part 38 of the carriage. The pawl is also held in relatively raised position by a spring 40 connected on its lower end to the pawl and at its upper end to a fixed part of the carriage. Also connected to the lever arm 22 as at 36 is a dimensionally stable cable 42 which extends rearwardly and around a pulley 44 mounted on a cross bar forming part of the carriage frame structure, and across the length of the carriage to end plate 14 where it is secured as at 45.

As shown in FIGURE 1 which illustrates the carriage in a centrally located position with respect to the typewriter frame, the cable 42 extends between rollers 47 mounted on the arms 46 of a Y-shaped yoke member 48 which is secured to the machine frame, and a roller 50 mounted on an actuator 52 adapted to be cycled between the arms 46 down and back to the normal position shown in FIGURE 1 upon depression of a repeat line space key (not shown). The mechanism for cycling the actuator 52 is fully described in Patent 2,728,438 which disclosure is incorporated by reference herein. The downward movement of the actuator 52 pulls down on the taut cable 42 thereby forming a loop 55 between arms 46 as shown in dotted line in FIGURE 1 and, as a consequence, to rock lever arm 22 causing the pawl 26 to slide forwardly in slot 28 into engagement with the ratchet 18 to effect rotation of the platen one increment. As is evident when the actuator 52 returns to normal the pawl 26 is retracted and the loop 55 is pulled straight under the action of return spring 3 4. Repeated cycling of the actuator 52 will effect repeat line spacing in similar fashion. It is to be noted that the cable 42 will be pulled down the same amount each time that the actuator 52 is cycled regardless of the position of the carriage relative to the frame thereby effecting uniform strokes of the pawl 26. The cable 42 may be made of any suitable dimensionally stable flexible material, such as metal wire, nylon-linen cord, etc.; the choice being dictated by the life requirements required or specified.

It should be understood that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

The invention claimed is:

1. In a typewriter or like machine having a carriage and a platen rotatably mounted on said carriage, an element on said carriage adapted when actuated to rotatably index said platen, a flexible dimensionally stable taut cable secured to said element and to the carriage frame structure, and means operable through a cycle for causing a loop in said cable whereby said line spacing element is actuated.

2. In a typewriter or like machine having a carriage and a platen rotatably mounted on said carriage, a line spacing element movably mounted on one end of said carriage, a flexible dimensionally stable cable secured to said line spacing element and to the other end of said carriage, and means for forming a loop in said cable thereby to move said line spacing element.

'3. In a business machine having a frame, a carriage mounted .on said frame and a platen rotatably mounted in said carriage, means for indexing said platen comprising a ratchet, a pawl adapted to engage and drive said ratchet, lever means .rotatably mounted on one end of said carriage and adapted when rotated to drive said pawl into engagement with said ratchet, a flexible dimensionally stable taut cable secured atone end to said lever means and at its other end to the other end of said carriage, and means including cyclically operable means for forming a loop in said cable whereby said lever means isrotated.

4. In a business machine having a frame, a carriage mounted on said frame and. a platen rotatably mounted in said carriage, a ratchet secured to one end of said platen, pawl means on the end of said carriage adjacent said ratchet adapted when actuated to engage and drive said ratchet whereby said platen may be rotatably 'indexed, a flexible dimensionally stable cable tautly secured between said pawl means and the other end of said carriage, and cyclic means on said machine frame operable to deflect said cable at any point between its ends thereby to actuate said pawl means.

References Cited in the file of this patent UNITED STATES PATENTS 

